DHI is an international consulting and research organization focused on water. It offers services, technologies, software tools and laboratories related to water. Its MIKE software can be used for reservoir inundation mapping through 2D overland flow modeling or integrated 1D-2D modeling using MIKE 11 and MIKE 21. Key features include dambreak structures, time-varying links and bathymetry, which allow modeling of breach development and dynamic inundation effects.

1. INTRODUCTION
MIKE by DHI Software for Reservoir
Inundation Mapping

2. Who are DHI?
About us
DHI is an independent, international consulting and research organisation
with the global objective of advancing technological development and
competence with respect to water, in all of its environments.
Services and technologies
We offer a wide range of consulting services and leading edge technologies,
software tools, environmental laboratories, and physical model test facilities
as well as field surveys and monitoring programmes.
International collaborating centres
DHI is designated as Collaborating Centre for the World Health Organisation,
WHO, and for the United Nations Environmental Programme, UNEP, and
furthermore as Advisory Centre for the Global Water Partnership.
DHI’s first commercially available software tool was MOUSE in 1985.

3. Who are DHI?
Research and development
Designated as a not-for-profit organisation DHI is able to invest 25% of its
human resources in research and development. Today we co-operate with
universities in Denmark and abroad and are recognised globally for our
innovation and expertise
Places and people
Our headquarters are located in Denmark, but more than half of the
employees work in one of DHI’s 29 offices around the globe. We are more
than 1000 employees worldwide.
For the past 20-years, with the assistance of key local representatives, DHI
has provided services and support for our UK clients from our head office in
Denmark. We feel that the time has come to formalise our presence in the
UK and, from 1st January 2012, we are pleased to announce that DHI
Water Environments (UK) Ltd has been established as a full UK
subsidiary.

4. MIKE by DHI Software
Read more…

5. MIKE by DHI Software - Performance
Speed
Parallelisation – many MIKE by DHI
products have been modified to take
advantage of multicore PCs, including;
MIKE 3 FMHD and MIKE 21 FMHD
(distributed memory – see graph), MIKE
21 SW, MIKE 21 BW, MIKE 21 HD, MIKE
21C, MIKE FLOOD and MIKE SHE
(shared memory).
64-bit architecture – with the shift from
32-bit to 64-bit hardware and software, The graph above shows MIKE 21 /
MIKE 3 FM speed-up using
the size of your models is no longer multicore PCs for Release 2011
constrained by memory. with distributed memory
architecture.
MIKE by DHI products are
delivered in standard 4-core
versions.

6. MIKE by DHI Software - Performance
Usability / Efficiency
EA2D ‘benchmarking’ – relative runtimes of
the five ‘main’ modelling packages. Lower
values means faster simulations. Green (and
the value 1) indicates the fastest package
(taken from the Environment Agency’s
'Benchmarking of 2D Hydraulic Modelling
Packages‘ report)
Average user ratings for most
frequently used 2D hydraulic
modelling packages (five is
excellent, one is poor) from the
Environment Agency’s ‘Desktop
Review of 2D Hydraulic Software
Packages’

7. OVERVIEW
Use of MIKE FLOOD for Reservoir Inundation
Modelling as a Result of Dam Failure

8. Reservoir Inundation Modelling
MIKE FLOOD 2D Overland Flow (MIKE 21)
An assessment of the potential area of
inundation, resulting from an uncontrolled
release of water from a reservoir (e.g. as a
consequence of dam failure), may be
modelled directly within MIKE 21 (in either
‘Classic’ single grid or flexible mesh versions)
utilising: -
• Point source inflows representing the likely
discharge hydrograph from a dam /
embankment failure (if known)
• Initial water level conditions within the
reservoir permitted to spill through an open
(static) breach, or through a standard 1D
control structure (e.g. gate structure)
MIKE 21 FM; dambreak
flow through a sharp
bend – Read more…

9. Reservoir Inundation Modelling
NB: There is some evidence to suggest that, where a detailed description of
supercritical to subcritical flow transition is required (e.g. in urban areas close
to a dam or embankment breach), modelling packages which employ a shock
capturing numerical scheme (MIKE 21 HDFM) perform better overall in
capturing the detail of the flow field.
The MIKE Animator video above presents surface water elevation results
from MIKE 21 / MIKE FLOOD FM for the critical dam break test case included
in the Environment Agency’s ‘Benchmarking of 2D Hydraulic Modelling
Packages’ report.
Read more…

10. Reservoir Inundation Modelling
MIKE FLOOD 1D-2D Integrated Inundation Model (MIKE 11 & MIKE 21)
There are numerous modules / features within MIKE 21, MIKE 11 and MIKE
FLOOD that will augment the above, and enable a more detailed assessment
of breach development and the resulting inundation: -
• MIKE 11 Dambreak structures (DB)
• MIKE FLOOD side structure links
• MIKE FLOOD time varying lateral links
• MIKE 21 time varying bathymetry
Other useful features: -
• MIKE 11 Seamless Mapping (DEM generation with river topography)
Results and presentation: -
• MIKE Animator
• Results Viewer
• Plot Composer

11. Reservoir Inundation Modelling
MIKE 11 Dambreak structures (DB)
A dambreak structure is a composite
structure composed of a structure
representing the flow over the crest
(rest flow structure) and another
structure representing the breach of
the dam. The breach can be modelled
in two different ways i.e. as a failure Crest failure
of the crest (breach structure) or as
piping failure of the dam (pipe failure
structure) followed by breach failure.
The flow through a dam breach may
be described in MIKE 11 through the
use of the energy equation or
alternatively a the calculation method
as implemented in National Weather Piping failure
Services (NWS) DAMBRK program.

12. Reservoir Inundation Modelling
MIKE 11 Dambreak structures can be applied as: -
• A regular structure in a MIKE 11 river branch as part of a MIKE FLOOD
1D-2D integrated inundation model
• A side structure that can be linked directly to a 2D domain in MIKE FLOOD
(encompassing, for example, rivers and floodplains)

13. Reservoir Inundation Modelling
MIKE FLOOD side structure links
MIKE FLOOD side structure links are
designed to model interaction between the
river model and the overland flow model
through Side Structures as defined in MIKE
11. Side structure links are explicit links, and
work in the same way as standard link.
Side structure links are used specifically for
dam break, embankment failure, pumping or
local spilling.
Local breaches

14. Reservoir Inundation Modelling
MIKE FLOOD time varying lateral links
The Levee Breach Generation is a tool for the creation of time varying levees.
By supplying a number of parameters defining the geometry of the levee
breach a time varying line series is created which may be used as input to the
MIKE FLOOD model.
Dynamic, spatially varying breaches

15. Reservoir Inundation Modelling
MIKE 21 time varying bathymetry – Landslide option (SG)
By including the landslide option in MIKE 21 ‘Classic’ grid, the user is able to
model the hydraulic effects of a time varying bathymetry. The effect of the
landslide is modelled by forcing terms representing the temporal dynamic
vertical deformation of the bathymetry. The landslide may be of submarine or
subaerial (e.g. for use in dam or levee breach) type. Also the effects of a
seismic seafloor deformation can be modelled using a time varying
bathymetry rather than a spatial varying initial surface elevation.

16. Reservoir Inundation Modelling
MIKE 21 time varying bathymetry – Dynamic Bathymetry Update (FM)
Initial condition
Final cross section
Allows users to apply time varying bathymetries to represent land slides,
levee failures or dune breaks

17. Reservoir Inundation Modelling
Example; dune break during 40-hour storm – water level variations

18. Reservoir Inundation Modelling
MIKE 11 Seamless Mapping
• Use the MIKE 11 mapping feature in coupled simulation
• Combines seamlessly 2D Bathymetry and 1D Cross sections (one
operation – no additional map-editing required)
Seamless map output – Combined MIKE 21 bathymetry and
MIKE 11 topography (Release 2012)

19. Reservoir Inundation Modelling
MIKE 11 GIS
GIS based pre-processing;
e.g. generation of cross
section from LIDAR

20. Reservoir Inundation Modelling
MIKE Animator
Dambreak examples

21. Reservoir Inundation Modelling
Further Considerations
Utilising the benefits of the full MIKE 21 FMHD model (inc. HD and NHD) and
extra add-on modules, the scope of any reservoir inundation modelling work
can be extended (particularly if the initial focus is on hydrodynamics only) to
account for other important consequences of a dam failure, including: -
• Sediment movement (morphological change); identification of downstream
areas at risk of scour, bank instability, deposition of eroded material,
secondary levee failure and their effects on river and floodplain
hydrodynamics
• Environmental impacts; assessment of habitat changes (both short and
long term), water quality issues and the assessment of potential
remediation measures
• Design of mitigation measures for the impacts of morphological and
environmental change
FYI: A special module of MIKE 21 is available that is based on a curvilinear
grid (MIKE 21C), which makes it suitable for detailed simulation of rivers and
channels, where an accurate description of bank lines is required. As such,
MIKE21C is particular suited for river morphological studies.

22. Reservoir Inundation Modelling
Dynamic Flood Hazard Mapping Tool* Further Considerations
Dynamic Flood Hazard Mapping with
ECO Lab (*included in MIKE FLOOD) ECO Lab
A numerical laboratory for ecological
modelling
• Open Equation solver for coupled
ordinary differential equations
• Designed for point descriptions of
processes of chemistry, ecology, etc
• All equations, parameters contained in
flexible, portable ECO Lab templates
(use DHI supported templates or
‘Most Appropriate way of calculating create your own)
• Templates include necessary spatial
Flood Hazard Rating in UK’ (RPS Group) information for 2D + 3D applications
• Integrated with DHI’s hydrodynamic
models: MIKE 11, MIKE 21 (hence
Image courtesy of RPS Group, UK MIKE FLOOD), MIKE 3 & MIKE SHE

23. Reservoir Inundation Modelling
Questions & Answers

24. THANK YOU
…and finally

25. The MIKE Community / Recent Applications
The 2012 MIKE by DHI UK User Group Meeting
Keynote Presentation
• Urban Flood Flows: The suburb of Merewether in Newcastle is providing engineers with critical data that will inform
emergency personnel on how to plan better for the floods which have wreaked havoc across Australia in the past few years.
A model of the suburb has been created in Sydney's Water Research Lab (Grantley Smith, University of Newcastle, NSW)
Client Presentations: MIKE BASIN – MIKE 21
• River Don - Integrated Catchment Management for Yorkshire Water: Integrated Catchment Management using MIKE BASIN
(Sally Bielby, JBA)
• Reservoir Discontinuance and River Restoration using MIKE 21 FMST: Design Background to a Reservoir Project – The
Hydraulic Model and lessons learnt (Mark Bailes, MWH)
• Maritime Archaeological Modelling using MIKE 21 - Later Prehistoric Seafaring in Scilly: Modelling of changing ocean/sea
conditions for the Holocene around North West Europe, with more detailed focus on the Isles of Scilly (Rodrigo Pacheco-
Ruiz, Southampton University)
Client Presentations: RENEWABLES - MIKE 21 – MIKE FLOOD – MIKE 11
• Wave resource assessment for Oyster farms using MIKE21: Ocean Power – Energy Field Characterisation (Ian Harris,
Aquamarine Power)
• Modelling the Severn Barrage: A Review of Modelling Strategies for a major UK Renewables Project (John Osment,
Halcrow)
• Tellisford Mill – Green Electricity from Run of River Hydro in an Historic Setting: A Low-head Hydro Scheme 7 years on from
the initial Flood-risk Assessment (Anthony Battersby, FBA / Mendip Power Group)
• Validation of a MIKE 21FM Spectral Wave model: For the purpose of an Offshore Wind Farm Coastal Processes
Assessment (Emma Holland, METOC)

26. The MIKE Community / Recent Applications
Client Presentations: MIKE 21 BW – MIKE 21 SW – MIKE 21 AD
• Wave Modelling with MIKE 21 BW & SW, and Cliff Recession Review: The ‘Baroque on Lamma’ Marina Project in Hong
Kong - A MIKE 21 SW & BW Model, and a Review of Empirical Techniques for Analysing Cliff Recession (Vicky Tonks, Mott
MacDonald)
• Long term coastal water quality predictions using convolutions: A MIKE 21/3 AD Water Quality Study (James Tomlinson,
ATKINS)
• Recent Experiences in Regional Scale FMHD Modelling: A Case Study of The Pentland Firth (Jack Shipton, ABPMER)
Client Presentations: FEFLOW – HABITATS – MIKE FLOOD 1-2-3D
• Aquifer Storage and Recovery in a Confined UK aquifer: FEFLOW - Artificial recharge modelling (Mike Streetly, ESI
International)
• Compliance with The Habitats Directive and Wetlands Ecology at a SSSI: Review of a Wetland Creation Project - 5 Years
On (Michael Limbrey, Montgomery Waterway Restoration Trust)
• 1-2-3D ‘Dee’ - River Dee Project: An Update and snapshot of a multi-dimensional MIKE Model at a single site ...plus Other
Random Musings (Simon Matthews & the UK DSP Team, DHI)
Free event!